Dockerfile: revert the user change PR that broke all APIs

Revert "cmd/puppeth: fix node deploys for updated dockerfile user"

Revert "Dockerfile.alltools: fix invalid command"

DialContext allows users to pass a Context object for cancellation.
Close closes the underlying RPC connection.

* fix typo

* fix typo

* fix typo

This avoids logging accept errors on shutdown and removes
a bit of duplication. It also fixes some goimports lint warnings.

* signer: introduce external signer command

* cmd/signer, rpc: Implement new signer. Add info about remote user to Context

* signer: refactored request/response, made use of urfave.cli

* cmd/signer: Use common flags

* cmd/signer: methods to validate calldata against abi

* cmd/signer: work on abi parser

* signer: add mutex around UI

* cmd/signer: add json 4byte directory, remove passwords from api

* cmd/signer: minor changes

* cmd/signer: Use ErrRequestDenied, enable lightkdf

* cmd/signer: implement tests

* cmd/signer: made possible for UI to modify tx parameters

* cmd/signer: refactors, removed channels in ui comms, added UI-api via stdin/out

* cmd/signer: Made lowercase json-definitions, added UI-signer test functionality

* cmd/signer: update documentation

* cmd/signer: fix bugs, improve abi detection, abi argument display

* cmd/signer: minor change in json format

* cmd/signer: rework json communication

* cmd/signer: implement mixcase addresses in API, fix json id bug

* cmd/signer: rename fromaccount, update pythonpoc with new json encoding format

* cmd/signer: make use of new abi interface

* signer: documentation

* signer/main: remove redundant  option

* signer: implement audit logging

* signer: create package 'signer', minor changes

* common: add 0x-prefix to mixcaseaddress in json marshalling + validation

* signer, rules, storage: implement rules + ephemeral storage for signer rules

* signer: implement OnApprovedTx, change signing response (API BREAKAGE)

* signer: refactoring + documentation

* signer/rules: implement dispatching to next handler

* signer: docs

* signer/rules: hide json-conversion from users, ensure context is cleaned

* signer: docs

* signer: implement validation rules, change signature of call_info

* signer: fix log flaw with string pointer

* signer: implement custom 4byte databsae that saves submitted signatures

* signer/storage: implement aes-gcm-backed credential storage

* accounts: implement json unmarshalling of url

* signer: fix listresponse, fix gas->uint64

* node: make http/ipc start methods public

* signer: add ipc capability+review concerns

* accounts: correct docstring

* signer: address review concerns

* rpc: go fmt -s

* signer: review concerns+ baptize Clef

* signer,node: move Start-functions to separate file

* signer: formatting

core: txpool stable underprice drop order, perf fixes

core/state: fix ripemd-cornercase in Copy

core/state: fix bug in copy of copy State

travis, appveyor: bump to Go 1.10.1

This commit is meant to allow ecosystem projects such as ethersphere
to minimize CI build times by specifying an environment variable with
the packages to run tests on.

If the environment variable isn't defined the build script will test
all packages so this shouldn't affect the main go-ethereum repository.